Carl in LA

Don't ask... I had to change out the disc pads on the front passenger wheel and I pushed the pistons back into the calipers to make room for the new pad and when it is reassymbled, no pressure on the brake pedal... Not able to build pressure by pumping pedal... did a bleed and tons of bubbles came out but even after it was clear of bubbles, still no pedal pressure. Yes, I was somewhat sloppy on pushing the pistons back into the calipers. Used a screwdriver wedged in there and the pistons did get cocked until I reset the driver to keep pushing... Any opinions on what failed???

Ok, since you were wondering why... My transmission cooler line cracked at the fitting where I had really tightened the hose clamp spewing tranny oil about the passenger side of the engine compartment, and the wheel and suspension system, and of course, the exhaust system. The electric fans blew it onto the disc brake! When did this happen??? On a date on Friday evening about 30-miles from home... This car is once again, tough love.

lyonsh

I'd start by bleeding the front driver's side, too. If you had air in the pass side, it's a pretty good bet there's air in the driver's side too.

Hopefully that's all it is. If not, there's a couple of nastier possibilities:

1. You may have damaged the piston seal in the caliper so the system is no longer sealed(do you see any fluid coming out from around there?).

2. If your MC is old, and you pumped the pedal to the floor, rust in the MC piston bore could have torn the cup seal, causing an internal bypass in the MC.

Carl in LA

Lyonsh - thanks for the feedback... helps me think out the situation...

Yes, I did see a drip or two coming off the bottom of the caliper but I forced myself to believe it was overflow from bleed screw... :rolleyes:

Master cylinder is new as is power booster. Gotta be just a huge old bubble or like you said, an o-ring blown out of its seat... either way I'm into a hundred dollar repair at the local (trusted) brake shop.

How about this for a challenge... driving the vette two miles through town to get to the brake shop with only the parking brake!!!

lyonsh

No thanks. :eek: I didn't get this old by doing stuff like that. :lol:

If you know it's the caliper, how about taking it off (it's not hard to do - one line and two bolts) and replacing it yourself. If you trust that brake shop, you can take the caliper and let them rebuild it. Good luck :cheers:

Carl in LA

Still interested in others experiences... Back TTT

WATTAC

Just to clarify, when you replaced the pads did you notice if the pistons in the caliper moved outward before you pressed them back in? Since Vette brakes have the "constant pressure" spring inside the calipers if you ever allow the pistons to move outward the caliper will fill with air. The seals on the pistons are built to only hold pressure in - fluid pressure that's due to pressing on the brake pedal. Any outward motion breaks that seal and air flows past the seal and into the caliper cylinder. Bleeding is the only fix.

If the seal was damaged when you pressed the piston in then you'd see lots of fluid coming out of that caliper when you tried to bleed the system, and of course you'd have little luck in purging the air. If while you're bleeding you see no leaking fluid then the system is solid (or you're not really pressurizing the system due to some other reason). I'm assuming you're seeing fluid leaving the bleed screw as you bleed the system, and you're having to periodically having to re-fill the master cylinder.

I'm also curious about the rear brakes. Your car should have two independent systems, front and back, and one should work regardless of the other. Have you lost all braking power?

Hope you've had better luck since the last post.

Andy

Aerovette

I'm with WATTAC, you should have had back brakes all along. I had the slider/keeper pin come out of my 75 and the peddle went to the floor when the shoes dislodged. I few pumps and I still had brakes to the rear. I'd rather wear those out than have to do the e-brake replacement.